C# - Generic enum type casting

Question

I have a few questions about generic classes with Enums.

First of all, I declared my class like this:

public class MyClass<TEnum> where TEnum : struct, IConvertible

But, I'm getting an error that states that my class cannot be used with type arguments.

Moreover, I need to convert the Enum's value to an Integer. How can I do that?

public void SomeMethod(TEnum value)
{
    int a = (int)value; // Doesn't work, need to cast to Enum first (?).
}

Thanks.

For the first part see http://stackoverflow.com/questions/6438352/using-enum-as-generic-type-parameter-in-c-sharp — Marcel N., Aug 05 '14 at 05:48
For the second, you can't redeclare `value` inside the function because it's already a parameter. — Marcel N., Aug 05 '14 at 05:49

score 1 · Answer 1 · answered Aug 05 '14 at 05:58

You already have what you need since you declared requirement IConvertible. Just use ToInt32 etc methods:

public class MyClass<TEnum> where TEnum: struct, IConvertible
{        
    public int SomeMethod(TEnum value)
    {
        return value.ToInt32(null);
    }
}

For example .NET type decimal is a struct and an IConvertble:

MyClass<decimal> test = new MyClass<decimal>();
Console.WriteLine(test.SomeMethod(150m));

For other classes be sure that you implement IConvertible.

score 0 · Answer 2 · answered Aug 05 '14 at 05:50

0

You have declared your generic type parameter to implement IConvertible and that interface has a ToInt32 method.

answered Aug 05 '14 at 05:50

jmcilhinney

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Hey, I know you from VBForums, hehe. I remember your dog avatar! Anyways, ToInt32 requires some FormatProvider...? Also, ToInt32 uses Convert. Isn't it easier to use Convert.ToInt32(value)? – user3865229 Aug 05 '14 at 05:50
You should be able to simply use `null` for the parameter value. You probably can just as easily use `Convert.ToInt32`. – jmcilhinney Aug 05 '14 at 06:03

C# - Generic enum type casting

2 Answers2